JP2008526522A5 - - Google Patents

Claims (21)

A method of joining at least two tube-like elements 1, 2 comprising at least one material that is difficult to weld or made from such a material,
A method comprising the steps of welding the elements together and then insulating the weld joint 3.   In the heat insulation step, the sleeve 4 and / or the sleeve 8 having heat insulation properties are arranged, and the region closest to the weld joint 3 and the weld joint of the elements 1 and 2 joined by the weld joint. The method of claim 1, comprising covering   Outside the weld joint 3 so as to surround the weld joint and the region of the elements 1, 2 so that the heat insulation step provides heat insulation to the weld joint with respect to the outside of the element. The method of claim 2, comprising disposing the sleeve 4. A method of joining elements 1 and 2 such as tubes, wherein at least the region to be joined by the weld joint is hollow,
The thermal insulation process covers the weld joint 3 and the region of the element closest to the weld joint so as to provide thermal insulation to the weld joint with respect to the interior of the element. 4. The method according to claim 2, further comprising disposing the sleeve (8) inside.   The sleeve 4 comprises an outer jacket 5 which is at least partly filled with a refractory material 6 such as ceramic fiber and which is arranged, for example, of metal or ceramic, and which is arranged outside the weld joint 3. The method according to claim 3.   The sleeve (8) comprises an inner jacket (9) which is at least partly surrounded by a refractory material (10), such as ceramic fiber, and which is arranged inside the element, for example made of metal or ceramics. 4. The method according to 4.   5. A method as claimed in any one of claims 2 to 4, wherein the sleeve includes at least one air gap arranged to cover the weld joint.   8. A method according to claim 2, wherein the sleeve and / or the sleeve are fixedly attached to at least one of the elements 1, 2 joined by a weld joint. . The method according to any of claims 1 to 8, wherein the elements 1, 2 such as tubes to be joined are hollow,
The end of one or more joining at least one of the elements 1 and 2, compared to the thickness of the remaining portion of the element, the thicker wall portion 7 is provided, the heat insulating material thick wall portion 7 from the A method comprising the step of attaching.   10. A method according to claim 9, comprising the step of installing one or more load bearing means, such as one or more load bearing shoulders, on the thicker wall 7 to support the insulation 4.   The method according to claim 2, wherein the sleeve is supported by a support means such as a support ring.   The method according to claim 1, wherein the heat insulating materials 4 and 8 include a refractory material or a ceramic material.   13. A method according to claim 12, characterized in that the insulation (4, 8) comprises a refractory fiber such as aluminum silicate. The material difficult to weld is
C: maximum 0.08 wt%,
Si: maximum 0.7 wt%,
Cr: 10 wt% to 25 wt%
Al: 1 wt% to 10 wt%
Mo: 1.5 wt% to 5 wt%
Mn: 0.4 wt% at maximum
14. A method according to any one of the preceding claims, characterized in that it comprises a dispersion strengthened alloy, such as an alloy containing the balance: Fe and impurities that are normally present.   The sleeve used for the method according to any one of claims 3 to 14, which includes a refractory material or a ceramic material. Sleeve for use in the method according to any one of claims 3 to 14 quoting Claim 2 Contact good beauty claim 2, characterized in that it comprises a refractory fiber such as aluminum silicate.   A refractory material 6 such as a ceramic fiber is at least partially filled and comprises an outer jacket 5 made of, for example, metal or ceramics. A sleeve used for the method according to any one of the above.   Claims 5 and 5 with reference to claim 4 and claim 2, characterized in that they comprise an inner jacket 9 which is at least partly surrounded by a refractory material 10 such as ceramic fiber, for example made of metal or ceramics. The sleeve used for the method in any one of 14.   The sleeve used for the method according to claim 2, wherein the sleeve is provided with at least one gap.   20. A method according to any of claims 1 to 14, or a corrosive condition of a sleeve according to any of claims 15 to 19, or use at elevated temperatures such as temperatures above 900C. The method according to any one of claims 1 to 14, or the use of the sleeve according to any one of claims 15 to 19 in a cracking furnace or a heat exchanger.